>>4042313You'll probably have to take separate exposures for the Landscape and Stars, then. You're GOING to get movement, in some way or another whether that be smooth startrails from long exposures or separate stuttery stars from individual exposures being stacked on top of each other. Most of the Milky Way widefield shooters in my group tend to photoshop two separate stacks together to get their nighttime widefield landscape shots.
Best thing I can suggest to you is to just experiment. You won't have to spend a lot of time outside since you can get enough data to capture a beautiful landscape/starfield in only a few minutes.
You can use this tool to calculate how much exposure time you need before getting trailing beyond a certain tolerance:
https://docs.google.com/spreadsheets/d/1tSEbji6V4rYz81COybiD5LWaekULIQReJy7kZCxQy78/edit?usp=sharing 